Insecta - Hymenoptera - Formicidae

Alternative combinations: Eoformica pingue, Liometopum pingue

Synonyms: Eoformica eocenica Cockerell 1921, Lasius terreus Scudder 1878

Full reference: S. H. Scudder. 1877. The First Discovered Traces of Fossil Insects in the American Tertiaries. Bulletin of the United States Geological and Geographical Survey of the Territories 3:741-762

Belongs to Eoformica according to B. Bolton 2012

Sister taxa: Eoformica expectans, Eoformica globularis, Eoformica magna

Type specimens:

• Eoformica pinguis: MCZ 2937, an exoskeleton (male with no wings). Its type locality is Fossil Cañon, which is in a Bridgerian lacustrine - large shale in the Green River Formation of Utah.
• Eoformica eocenica: USNM 66932, an exoskeleton. Its type locality is USGS 17-3; Smith's Ranch, in the vicinity of Cathedral Bluffs, which is in a Bridgerian lacustrine - large shale in the Green River Formation of Colorado.
• Lasius terreus: 14692, an exoskeleton. Its type locality is Petrified fish cut (Richardson Coll), which is in a Bridgerian lacustrine - large diatomite/shale in the Green River Formation of Wyoming.

Average measurements (in mm): abdomen length 3.10, antennae length 2.65, body 7.37 x 1.99, thorax 3.00 x 1.80